Response Inhibition After Traumatic Brain Injury (TBI) in Children: Impairment and Recovery

Children who experience traumatic brain injury (TBI) often show cognitive impairments postinjury, some of which recover over time. We examined the recovery of motor response inhibition immediately following TBI and over 2 years. We assessed the role of injury severity, age at injury, and lesion characteristics on initial impairment and recovery while considering the role of pre-injury psychiatric disorder. Participants were 136 children with TBI aged 5–16 years. Latency of motor response inhibition was measured with the stop-signal task within 1 month of the injury and again at 3, 6, 12, and 24 months. The performance of the TBI participants at each measurement occasion was standardized with 117 children of similar age, but without injury. Residualized latency scores were calculated. Growth curve analyses showed an initial impairment in response inhibition and improvement over the 2 years following injury. Younger TBI patients were initially more impaired although they exhibited greater recovery of response inhibition than did older TBI patients. Longer duration of coma, but not reactivity of pupils or Glasgow Coma Scale score, predicted initial deficit. Lesion characteristics or pre-injury attention deficit hyperactivity disorder did not predict initial impairment or recovery. Replication with longitudinal testing of a comparison group of children sustaining extracranial injury is necessary to confirm our findings.     

Diffusion Tensor Imaging of White Matter Tracts in the Dog Brain

Diffusion weighted imaging sequences are now widely available on Magnetic Resonance Imaging (MRI) scanners. Diffusion Tensor Imaging (DTI) of the brain is able to show white matter tracts and is now commonly used in human medicine to study brain anatomy, tumors, structural pathways,… The purpose of this study was to show the interest of DTI to reveal the white matter fibers in the dogs' brain. DTI MR Images for this study were obtained with a 3 T system of 4 dogs euthanized for other reasons than neurological disorders. Combined fractional anisotropic (FA) and directional maps were obtained in the first 2 hours after death. The heads were amputated immediately after scanning and stored in 10% formalin until preparation for dissection. An experienced anatomist tracked white matter tracts with clinical relevance using the scanner software. The selected tracts were REFVIDume rendered and correlated with gross dissection. Using DTI we were able to track relevant neurological connections, such as the corticospinal tract, the optic and the cerebellar tract. The three dimensional anatomy is better presented using modern visualization techniques. DTI seems to be a valuable tool in order to present clinically relevant white matter tracts to neurological clinicians and researchers. Anat Rec, 296:340–349, 2013. © 2013 Wiley Periodicals, Inc.     

Discourse Macrolevel Processing After Severe Pediatric Traumatic Brain Injury

The purpose of this study was to determine if discourse macrolevel processing abilities differed between children with severe traumatic brain injury (TBI) at least 2 years postinjury and typically developing children. Twenty-three children had sustained a severe TBI either before the age of 8 (n = 10) or after the age of 8 (n = 13). The remaining 32 children composed a control group of typically developing peers. The groups' summaries and interpretive lesson statements were analyzed according to reduction and transformation of narrative text information. Compared to the control group, the TBI group condensed the original text information to a similar extent. However, the TBI group produced significantly less transformed information during their summaries, especially those children who sustained early injuries. The TBI and control groups did not significantly differ in their production of interpretive lesson statements. In terms of related skills, discourse macrolevel summarization ability was significantly related to problem solving but not to lexical or sentence level language skills or memory. Children who sustain a severe TBI early in childhood are at an increased risk for persisting deficits in higher level discourse abilities, results that have implications for academic success and therapeutic practices.     

Discourse Macrolevel Processing After Severe Pediatric Traumatic Brain Injury

The purpose of this study was to determine if discourse macrolevel processing abilities differed between children with severe traumatic brain injury (TBI) at least 2 years postinjury and typically developing children. Twenty-three children had sustained a severe TBI either before the age of 8 (n = 10) or after the age of 8 (n = 13). The remaining 32 children composed a control group of typically developing peers. The groups' summaries and interpretive lesson statements were analyzed according to reduction and transformation of narrative text information. Compared to the control group, the TBI group condensed the original text information to a similar extent. However, the TBI group produced significantly less transformed information during their summaries, especially those children who sustained early injuries. The TBI and control groups did not significantly differ in their production of interpretive lesson statements. In terms of related skills, discourse macrolevel summarization ability was significantly related to problem solving but not to lexical or sentence level language skills or memory. Children who sustain a severe TBI early in childhood are at an increased risk for persisting deficits in higher level discourse abilities, results that have implications for academic success and therapeutic practices.     

Social Competence in Young Children With Inflicted Traumatic Brain Injury

As infants develop skills that allow for increasing independence in social and cognitive domains, they acquire the ability to identify goals, sequence behaviors to carry out goals, and to flexibly use strategies for attaining goals in both social and independent play contexts. Little is known about how brain injury in young children may disrupt the precursors to such executive processes. In this study, we examined social and cognitive competence in 25 infants ages 3 to 23 months who sustained moderate to severe traumatic brain injury (TBI) secondary to physical abuse and in 22 healthy community comparison children. Children with TBI were evaluated an average of 1.6 months after the injury. A toy-centered activity with the examiner was used to capture joint attention and social behavior and an exploratory toy play situation was used to measure independent goal-directed play. The inflicted TBI group showed significant reduction in both social and cognitive domains relative to the comparison group. Canonical correlation analyses disclosed that inflicted TBI was associated with reduction in (a) initiation of social interactions, (b) responsiveness to interactions initiated by the examiner, (c) positive affect, and (d) compliance. The groups performed comparably on indexes of gestural and verbal communication and for the occurrence of negative affect. Joint attention was an area of vulnerability for the TBI group in both social initiation and response contexts. Although general cognitive and motor scores were lower in the inflicted TBI group, the complexity of independent toy play did not differ across groups. Early brain injury causes significant disruption in behaviors regulating initiation and responsiveness in social contexts. Longitudinal follow-up will characterize the long-term consequences of early disruption in joint attention and other behaviors on the development of social and cognitive precursors to executive processes.     

First-Order Theory of Mind Skills Shortly After Traumatic Brain Injury in 3- to 5-Year-Old Children

Post-acute effects of early childhood traumatic brain injury (TBI) on first-order theory of mind (ToM) skills were examined in 86 children with orthopedic injury (OI), 42 children with moderate TBI, and 17 children with severe TBI aged 3 to 5 years at the time of injury. Three-year-olds with TBI performed more poorly than 3-year-olds with OI on an appearance–reality task. The severe TBI group was impaired on false-contents tasks compared to the moderate TBI and OI groups. Age and IQ were strong predictors of ToM performance; however, the relationship between ToM and IQ was not as strong for children with TBI.     

Attention Deficit Hyperactivity Disorder in Children and Adolescents Following Traumatic Brain Injury

To better characterize pediatric psychopathology after neurological insult, secondary attention deficit hyperactivity disorder (SADHD)-or ADHD that develops after traumatic brain injury (TBI)-and its clinical and neuroimaging correlates were investigated. Outcome data were available for 118 children, ages 5 through 14 at the time of hospitalization following TBI (severe TBI n = 37; mild-moderate TBI n = 57) and orthopedic injury (n = 24). Standardized psychiatric, adaptive functioning, cognitive functioning, family functioning, and family psychiatric history assessments were conducted on all participants. Severity of injury and neuroimaging lesion assessments were conducted on TBI participants only. The diagnosis of SADHD was mutually exclusive with preinjury ADHD, which occurred in 13 of 94 TBI participants and 4 of 24 orthopedic injury participants. SADHD occurred in 13 of 34 eligible participants with severe TBI but resolved in 4 of 13 of these participants. SADHD also occurred in 1 of 8 eligible moderate TBI participants, only in the presence of preinjury ADHD traits and 3 of 39 of eligible mild TBI cases. SADHD occurred in 1 of 20 of eligible participants with orthopedic injury without any brain injury. SADHD was significantly associated with TBI severity recorded by categorical and dimensional measures, intellectual and adaptive functioning deficits, and personality change due to TBI, but not with lesion area or location. These results suggest that SADHD is a clinically important syndrome after severe TBI in children and adolescents.     

Attention Deficit Hyperactivity Disorder in Children and Adolescents Following Traumatic Brain Injury

To better characterize pediatric psychopathology after neurological insult, secondary attention deficit hyperactivity disorder (SADHD)-or ADHD that develops after traumatic brain injury (TBI)-and its clinical and neuroimaging correlates were investigated. Outcome data were available for 118 children, ages 5 through 14 at the time of hospitalization following TBI (severe TBI n = 37; mild-moderate TBI n = 57) and orthopedic injury (n = 24). Standardized psychiatric, adaptive functioning, cognitive functioning, family functioning, and family psychiatric history assessments were conducted on all participants. Severity of injury and neuroimaging lesion assessments were conducted on TBI participants only. The diagnosis of SADHD was mutually exclusive with preinjury ADHD, which occurred in 13 of 94 TBI participants and 4 of 24 orthopedic injury participants. SADHD occurred in 13 of 34 eligible participants with severe TBI but resolved in 4 of 13 of these participants. SADHD also occurred in 1 of 8 eligible moderate TBI participants, only in the presence of preinjury ADHD traits and 3 of 39 of eligible mild TBI cases. SADHD occurred in 1 of 20 of eligible participants with orthopedic injury without any brain injury. SADHD was significantly associated with TBI severity recorded by categorical and dimensional measures, intellectual and adaptive functioning deficits, and personality change due to TBI, but not with lesion area or location. These results suggest that SADHD is a clinically important syndrome after severe TBI in children and adolescents.     

Modeling of Longitudinal Academic Achievement Scores After Pediatric Traumatic Brain Injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

Neuropsychological Deficit and Academic Performance in Children and Adolescents Following Traumatic Brain Injury

Evaluated the utility of neuropsychological testing in predictingacademic outcome in children 1 year following traumatic braininjury (TBI). Fifty-one schoolage children who were admittedto hospital after TBI were assessed with a battery of neuropsychologicalmeasures at 3 months postinjury. Academic achievement was assessedat 3 and 12 months postinjury. The neuropsychological batteryincluded intelligence testing and measures of memory, learning,and speed of information processing. Academic outcome was assessedin terms of post-TBI changes in reading, spelling, and arithmetic;changes in teacher ratings of school performance; and changein school placement. According to logistic regression analysis,change in placement from regular to special education at 1-yearpost-TBI was predicted by injury severity and by neuropsychologicalperformance at 3 months post-TBI. Findings suggest that neuropsychologicaltesting is useful in identifying children with special educationalneeds subsequent to TBI.     

Modeling of Longitudinal Academic Achievement Scores After Pediatric Traumatic Brain Injury

In a prospective longitudinal study, academic achievement scores were obtained from youth 5 to 15 years of age who sustained mild-moderate (n = 34) or severe (n = 43) traumatic brain injuries (TBI). Achievement scores were collected from baseline to 5 years following TBI and were subjected to individual growth curve analysis. The models fitted age at injury, years since injury, duration of impaired consciousness, and interaction effects to Reading Decoding, Reading Comprehension, Spelling, and Arithmetic standard scores. Although scores improved significantly over the follow-up relative to normative data from the standardization sample of the tests, children with severe TBI showed persistent deficits on all achievement scores in comparison to children with mild-moderate TBI. Interactions of the slope and age parameters for the Arithmetic and Reading Decoding scores indicated greater increases over time in achievement scores of the children injured at an older age, but deceleration in growth curves for the younger children with both mild-moderate and severe TBI. These results are compatible with the hypothesis that early brain injuries disrupt the acquisition of some academic skills. Hierarchical regression models revealed that indexes of academic achievement obtained 2 years following TBI had weak relations with the duration of impaired consciousness and socioeconomic status. In contrast, concurrent cognitive variables such as phonological processing and verbal memory accounted for more variability in academic scores. Given the significant and persistent decrement in basic academic skills in youth with severe TBI, it is clear that head-injured youth require intensive, long-term remediation and intervention not only of the academic skills themselves, but also of those cognitive abilities that support the development and maintenance of reading and math.     

Memory Functioning Following Traumatic Brain Injury in Children With Premorbid Learning Problems

This study examines the memory functioning of 25 children who sustained a traumatic brain injury (TBI) and who had prior learning problems, 48 children with TBI who did not have prior learning problems, and 23 noninjured controls. The children with TBI and prior learning problems displayed significantly worse memory abilities than both the control participants and the children with TBI and no prior learning problems. They differed significantly from these 2 groups on measures of general memory, verbal memory, sound-symbol learning, and attention. The results suggest that children with premorbid learning problems who sustain TBI have less cognitive reserve and a lower threshold for the expression of cognitive impairments in areas that reflect preexisting learning and language problems, compared to children without premorbid learning problems.     

Selective Changes in Executive Functioning Ten Years After Severe Childhood Traumatic Brain Injury

Pediatric traumatic brain injury (TBI) impacts on children's executive functions, but little is known of how such deficits evolve in the long term. Forty adolescents with TBI were assessed ten years post-injury and compared to 19 typically developing participants on a range of executive measures (attentional control, cognitive flexibility, goal setting, information processing). Children with mild or moderate TBI performed within age expectations on all tests; however, those with severe injuries had poorer performance on goal setting and processing speed tasks. Childhood TBI may result in subtle lasting changes in complex executive skills, which could require ongoing support into adulthood.